1. Technical Field
The present invention relates to spectacle lenses formed of a pair of lenses for left and right eyes, spectacles, and a method for manufacturing the spectacle lenses.
2. Related Art
JP-A-2002-202482 discloses a method for designing and manufacturing left and right spectacle lenses that form spectacles based on different prescriptions including dioptric power of left and right eyes in such a way that optical performance is ensured within an acceptable range and the appearance of the lenses is ensured to be good-looking at the same time. In the method, when the difference between the prescriptions including dioptric power of the left and right eyes is greater than or equal to a predetermined value, lens design is so performed that balanced binocular vision is achieved by designing the curvatures of first and second curved refraction surfaces of each of the left and right spectacle lenses in such a way that not only do the left and right spectacle lenses satisfy the respective prescriptions including dioptric power and does optical performance of each of the lenses falls within an acceptable range but also the curvatures of the first and second curved refraction surfaces of at least one of the left and right spectacle lenses are so selected that the difference in the curvature of the first curved refraction surface between the left and right spectacle lenses falls within a predetermined range.
A spectacle lens is selected, designed, and/or manufactured from a variety of viewpoints in accordance with states and/or specifications of a user (wearer). In recent years, even a commercially available plastic lens has a high refractive index ranging from 1.6 to 1.7, and a plastic lens having a higher refractive index is being developed. Further, an aspheric surface is introduced to correct aberrations in a more satisfactory manner, whereby even a plastic lens having large power (dioptric power) is not very thick (a peripheral portion of a lens is not very thick) and aberrations are well corrected. The thus designed spectacles fit well to a wearer and allow the wearer to view an object in a satisfactory manner. There is, however, a demand to provide spectacles that allow the wearer to view an object in a more satisfactory manner.